Because the earth's orbit is slightly elliptical, the earth actually gets closer to the sun during part of the year. when the earth is closer to the sun its orbital speed is

speed is maximum

Explanation:

When the earth is closer to the sun the speed is maximum.

According to the conservation of angular momentum, when no external torque is acting, then the angular momentum of the system remains constant.

So, mass x velocity x distance remains same. As the planet is nearest to the sun, so its velocity should be maximum to keep the angular momentum constant.

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete